When Odysseus returns to Ithaca, disguised as a beggar, he learns a great deal about the suitors by observing their behavior, especially their behavior toward him. According to the rules of Greek hospitality, the suitors should be willing to share their food and drink generously, especially because it isn't even their own resources that they'd be sharing -- the goods actually belong to Odysseus and his family! This is all the more reason they shouldn't be stingy. However, Antinous calls him a "pest" and says that he is spoiling their feast before actually throwing a stool at him. The suitors also force him to fight another local beggar, Irus, and even a slave-maid of Penelope mocks him and treats him poorly. He learns that these are really terrible, awful people who deserve no pity from him.
However, when Penelope hears that a poor man was struck in her home, she feels badly and asks for him to be brought to her so that she can ask him if he has any news of Odysseus. When they meet that night, her descriptions of how she's been trying to delay the suitors and questions about Odysseus convince him of her continued loyalty and love. Odysseus convinces her that he knows her husband and that he is on his way home and will be there soon with a great deal of treasure that he has collected in his travels.